Although the heightened risk is low, women with leiomyomas are more likely to experience obstetric complications, Missouri-based researchers report in the November issue of Obstetrics and Gynecology.
Dr. Molly J. Stout and colleagues at Washington University School of Medicine, St. Louis, came to this conclusion after retrospectively studying data on more than 64,000 women with singleton pregnancies. All had been examined by ultrasound at the second trimester and had complete obstetric follow-up information.
The incidence of leiomyomas was 3.2%. In this group, after adjustment, the incidence of breech presentation was elevated (odds ratio, 1.5). Corresponding odds ratios for placenta previa were 2.2, for placental abruption, 2.1, for Cesarean delivery, 1.2, and for birth at less than 37 weeks, 1.5.
Among other significantly elevated risks was that of intrauterine fetal death in women with a fetus with growth restriction. This was experienced by 3.9% of the leiomyoma group compared to 1.5%, of the others (adjusted odds ratio, 2.5). However, say the investigators, “Given the observational nature of these data, causality cannot be confidently concluded.”
As Dr. Stout told Reuters Health by email, “there was a slightly increased risk of stillbirth in women with fibroids and a small-for-gestational-age fetus. Although the overall risk of these complications remains small, this information is important for patient counseling and physician decision making, particularly in the context of a small-for-gestational-age fetus.”
There was no increased risk of intrauterine growth restriction or preeclampsia in women with leiomyomas.
Based on this large cohort, the team concludes, “It appears that although leiomyomas are cytologically benign, they may not be clinically benign, and particular attention to individual counseling and appropriate clinical interventions may be beneficial in women with this common uterine pathology.”0